Trackball



FIG. 1 is a perspective view of trackball showing the new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a left elevational view thereof;

FIG. 5 is a right elevational view thereof;

FIG. 6 is a rear elevational view thereof; and,

FIG. 7 is a front elevational view thereof.

The broken lines showing environmental structure is for illustrativepurposes only and form no part of the claimed design.

The ornamental design for a trackball, as shown and described.